Dialog Resize not working

[sanx]

I am resizing my dialog and then moving it to top-left of screen.
if i do so, i am unable to resize my dialog with mouse button. but if i move my dialog using mouse then resizing works fine. my code is
rect.setWidth(rect.width()/2);
rect.setHeight(rect.height()/2);
this->setGeometry(rect);
this->move(rect.topRight())
can anyone help??